Electric-arc lamp.



PATENT'ED APR. 19, 1904.

1; W. PBRGIVAL'. ELECTRIC ARG'LAMP.

APPLICATION FILED JAN. 23, 1399.

N0 MODEL.

Patented Aprii 19, 1904.-

UNITED STATES-PATENT OFFICE.

ISAAC W. PERCIVAL, OF ST. LOUIS, MISSOURI, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

'ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent N0. 757 ,958, dated April 19, 1904.

Application led January 23, 1899. Serial No. '703,164- (No model.)

T0 all 'whom it may concern:

Be it known that I, ISAAC W. PERQIVAL, a subject of the Queen of Great Britain, residing in the city of St. Louis, State of Missouri, have invented a certain new and useful Improvement in Electric-Arc Lamps, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompany-` ing drawings, forming part of this specification, in which Figure 1' is a side elevational view of my improved electric-arc lamp, the large or outer globe being omitted. Fig. 2 is a similar view of the lower portion of the lamp as seen at right angles to Fig. 1. Fig. 3 is a cross-sectional View n line 3 3 of Fig. 2. Fig. 4 is an enlarged View showing a plurality of pairs of carbons in an inclosing globe, and Fig. 5 is a top plan v1ew of the cap for said inclosing globe.

Heretofore, so far asI am aware, no single necessary to burn two lamps in series or, if

only one lamp is employed, to introduce resistance consuming the equivalent of current used by another lamp in order that the single lamp may produce a white light.

My improvement consists in placing two sets of carbons (or carbon electrodes) in series with each other, which sets are arranged to feed independently, both being governed by a single magnetic feed mechanism and both arcs iiiclosed in a single small inclosing globe.

This lamp is especially adapted to voltages of two hundred and twenty volts and upward; but it is obvious that more than two sets of carbon electrodes maybe employed by reason of the possibility of using three sets of carbon electrodes for three'hundred andthirty volts, four sets for four hundred and forty volts, &c. v

In carrying out my improvement I inclose the sets of carbon electrodes which are in series iny a single' small inclosing globe.

The stationary electrodes A are mounted in supports B, which are insulated from each other. The movable electrodes C are independently supported by clamping-disks D, arranged on a suitable post or supporting-rod and governed by a single magnetic feed mechanism in such manner that said movable electrodes are fed independently of each other. These movable electrodes C enter the inclosing globe (marked E in the drawings) through suitable openings in the cap or cover F on said globe, which cap is preferably made of y metal and provided with porcelain or other insulationthimbles G, which serve as guides for the movable electrodes. This inclosing globe while not exactly air-tight excludes oxygen toA a great extent and preserves the electrodes, so that they will burn a much longer period of time than where open to the atmosphere. By providing two or more sets of electrodes in a single small inclosing globe the air that enters the globe in the absence of arcs between the electrodes is more quickly neutralized by a plurality of arcs than is possible where a single arc is employed in a small inclosing The presence of a small inclosingl globe. globe changes the operative conditions of a lamp, as it permits lhigher voltages and increases the life of the electrodes over and above the voltage that could be employed in connection with and the length of life of the electrodes in an open arc-lamp. The wiring of these pairs of electrodes is such that the crater, as it is called, is formed on the upper or movable electrode of each set, vso as to obtain the greatest benefit from the luminating properties of the lamp. lhe wiring for the electrodes is shown clearly in Fig. l, where l indicates the inlead-wire, which is preferably attached to the lamp at its top and connected to the solenoid-magnets 2, whence it passes through wire 3 to one of the movable electrodes C, thence through the fixed electrode and through wire 3 to the supporting-sleeve of the other movable electrode C, downwardly through said other movable electrode to its iixed companion electrode and through the metallic support B of said last-named lixed electrode to wire 4, back to and through the resistance-coil 5, preferably arranged at the top of the lamp and supported by porcelain insulators, thence through a switch 6. and out through the return-wire 7. Suitable gripping devices 8 are provided for the movable electrodes, and dash-pots 9 are also preferably employed in connection with the rods which carry the movable electrode for well-known purposes.

From the above it will be seen that my improvement consists in the employment of a plurality of pairs of electrodes whose arcs are enveloped in a single small inclosing globe, said pairs of electrodes being' connected in series and supplied from a direct-current con stant potential sourc The arcs between the pairs of electrodes are extinguished when the electrodes of any one of the sets in series burn away. This opens the circuit and brings the points of all of the sets of electrodes in the lamp in contact with each other, and thus reestablishes the circuit and energizes the magnets for the purpose of operating the movable electrodes and separating' the sets of electrodes at approximately equal distances apart. By having the movable electrodes fed independently of each other, the feeding mechanism being under the control of a single magnetic device, equal distances between the lixed and movable electrodes of each set or pair are su bstantially preserved at all times, which is advantageous in that the arcs being of the same length will give out equal quantities of light. The use of a sing'le small inclosing globe for enveloping all of the arcs of the pairs of electrodes burning in series in a single lamp is advantageous in that a higher voltage can be employed than where an open arc is used. Furthermore, the inclosing globe will greatly lengthen the lives of the electrodes, so that the necessity for trimming the lamps frequently is avoided.

One of the prime objects of my invention is to produce a clear white light, which has, before my invention, never been produced in a single lamp burning two hundrd and twenty volts and above. Heretofore wherea single lamp has been employed in connection with the circuit of such a high voltage the electrodes were separated too far apait`say, for illustration, one and one-q uarter inches apartthat a blue or purple light resulted. NV here two or more sets of electrodes are arrangeifl in series in a. single small inclosing globe across acircuit of, say,two hundred and twenty volts and over, the pairs of electrodes are not separated so far apart and a pure white light results.

Another factor in the use of lamps such as illustrated in the accompanyingdrawings is the advantage of my lamp over those usually employed to-day, wherein if two separate lamps are arranged in series and are used at diiierent places by different custoiners should the customers disagree as to the time of burning of either of said lamps the extinguishment of one would mean the extinguishment of the other. Further, if there was but one customer for one lamp it would be necessary before giving him the advantage of the white light to place a second lamp in the vicinity whose hours of burning would necessarily have to agree with the first lamp placed in position, or vice versa, or a dead resistance would have to be introduced in the single lamp with its consequent loss. VVhei-e a single lamp having but one pair of electrodes is used in a circuit of high voltage*say one hundred and eighty volts or above--only a small portion of this voltage is available to said siii'igle lamp, thus rendering it ineilicient. These objections are not present where the lamp shown in the accompanyingdrawings is used, as one lamp can be burned across a circuitof two hundred and twenty volts or over, there being' no occasion to use two such lamps in series, and consequently the disiulvantage of burning two single lamps is obviated.

My lamp is efficient, produces a pure white light, and is not dependent upon the introduction of dead resistance (except for the usual purpose of steadying the are) or the operation or inoperation of any lamp connected in series therewith.

Having thus described my invention, what I claim, and desire to secure hy Letters .latent, is

1. ln an electric-lighting system supplied with direct current of consta-ut potential and high voltage as described, an electric-arc lamp, comprising a plurality of fixed electrodes, a plurality of movable clcctrodis coi'perating respectively with said fixed electrodes, a single small light-emitting globe for inc-losing the arcs produced between said electroifles, means for supporting the lixed electrodes out of direct electrical connection with eachother and so that their endsare in proximity to each other in said globe, a cap or cover for said globe provided with openings for the approximately air-tight passage therethrough of the movable electrodes, connections joining' all of said electrodes in series, and a. single niiag i netic control mechanism for said movable electrodes. A 2. In an electric-light1ng system supplied with direct current of constant potential and IOO movable electrodes, connections joining all of said electrodes in series, a single magnetic control mechanism for said movable electrodes, and means for permitting said movn* able electrodes to feed independently.

In testimony whereoil I hereunto aiiX my signature,in the presence of two witnesses,this 21st day of January, 1899.

ISAAC W. PERCIVAL.

Witnesses F. R. CORNWALL, A. S. GRAY. 

